U.S. patent number 5,620,339 [Application Number 08/290,714] was granted by the patent office on 1997-04-15 for electrical connectors.
This patent grant is currently assigned to ITT Industries Ltd.. Invention is credited to Ian J. Gray, Melvin D. White.
United States Patent |
5,620,339 |
Gray , et al. |
April 15, 1997 |
Electrical connectors
Abstract
A connector (e.g. coaxial connector) comprises a tubular body
structure (22, 23) with an axially extending bore therein for
receiving an incoming cable (40) (e.g. coaxial) and for
accommodating electrically-conductive contact-making means (31)
located adjacent a part of the cable within the tubular body
structure and electrically coupled with contact means (32) (e.g.
pin contact) of the connector. Axially displaceable means (35) at
least partly received by the tubular body structure (22, 23) causes
the contact-making means (31) to make good electrical contact with
a conductor (44) of the cable (40) (e.g. control conductor of
coaxial cable) in response to a predetermined axial displacement of
the displaceable means (35). The displaceable means (35) has a
first positive hold position relative to the tubular body structure
in which position the displaceable means acts solely to retain
other connector components within the tubular body structure (22,
23). By the predetermined axial displacement of the displaceable
means (35) from the first positive hold position to a further
positive hold position good electrical contact is established
between the contact-making means (31) and the conductor (44) of the
cable (40).
Inventors: |
Gray; Ian J. (Winchester,
GB3), White; Melvin D. (Winchester, GB3) |
Assignee: |
ITT Industries Ltd.
(Basingstoke, GB2)
|
Family
ID: |
27266049 |
Appl.
No.: |
08/290,714 |
Filed: |
December 27, 1994 |
PCT
Filed: |
January 22, 1993 |
PCT No.: |
PCT/GB93/00142 |
371
Date: |
December 27, 1994 |
102(e)
Date: |
December 27, 1994 |
PCT
Pub. No.: |
WO93/16506 |
PCT
Pub. Date: |
August 19, 1993 |
Foreign Application Priority Data
|
|
|
|
|
Feb 14, 1992 [GB] |
|
|
9203234 |
May 14, 1992 [GB] |
|
|
9210375 |
Nov 13, 1992 [GB] |
|
|
9223824 |
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Current U.S.
Class: |
439/578; 439/584;
439/784 |
Current CPC
Class: |
H01R
4/489 (20130101); H01R 4/5025 (20130101); H01R
9/05 (20130101); H01R 9/0518 (20130101); H01R
4/50 (20130101) |
Current International
Class: |
H01R
9/05 (20060101); H01R 4/50 (20060101); H01R
4/48 (20060101); H01R 009/05 () |
Field of
Search: |
;439/578-585,752,351,352,357,395,404,851,783,805-807,784 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Pirlot; David L.
Attorney, Agent or Firm: Peterson; Thomas L.
Claims
We claim:
1. An electrical connector comprising a tubular body structure (22,
23) having an axially extending bore (37) therein for receiving an
incoming cable and for accommodating electrically-conductive
contact-making means located adjacent a part of the cable within
the tubular body structure and electrically coupled with contact
means of the connector, and axially displaceable means (36) at
least partly received by the tubular body structure and effective
to cause the contact-making means to make good electrical contact
with a conductor of the cable in response to a predetermined axial
displacement of the displaceable means, in which the displaceable
means has at least one positive hold position relative to the
tubular body structure in which position the displaceable means
acts solely to retain other connector components within the tubular
body structure and in which the predetermined axial displacement of
the displaceable means from the positive hold position to a further
position establishes good electrical contact between the
contact-making means and the conductor of the cable;
said axially displaceable means having a groove or projection, and
said connector including a tubular latching member that is slotted
to provide a plurality of radially deflectable arms having a groove
or projection thereon for making snap engagement with spaced
projections or grooves on the axially displaceable means.
2. The connector described in claim 1 wherein:
said contact has a pin front portion, and said contact rear portion
is integral with said pin front portion and is in the form of a
tube with a plurality of slots that form said tines.
3. An electrical connector comprising:
a body structure having a cable-receiving bore with an axis;
a contact lying in said bore, said contact having a pin front
portion and having a contact rear portion that is integral with
said pin front portion, said rear portion having an inside surface
for receiving a wire conductor, said rear portion having an outer
surface, and said rear portion having at least three tines which
are deflectable to clamp to said wire conductor;
a clamping member lying in said bore, said clamping member having
an inside that is of smaller diameter than said contact rear
portion;
said clamping member being movable relative to said contact along
said axis, to compress the outside surface of said contact rear
portion so said at least three tines of said contact rear portion
clamp to said wire conductor;
said contact rear portion being in the form of a tube with a
plurality of slots that form said tines.
Description
This invention relates to electrical connectors.
The invention relates especially, but not exclusively, to
electrical connectors of the coaxial type in which an electrical
connection is made between the central conductor of an incoming
coaxial cable and contact means of the connector without the need
for crimping and/or other tools.
A connector is known from U.S. Pat. No. 3,761,870 in which, a
cylindrical connector body is provided with a contact having one
end in the form of a collet like clamp. A resilient clamping
element which has a through bore slides over the collet and is
compressible onto the collet to effect clamping of a conductor by
rotation of a hexagonally headed male threaded component which
cooperates with a female thread in the cylindrical body to urge a
clamping member to compress the resilient clamping element onto the
collet. In order to effect clamping two hands are required in order
to hold the body and rotate the nut and there is uncertainty about
the degree of clamping which results as pressure is gradually
applied during the screwing action.
Another connector is known from U.S. Pat. No. 3,847,463 which has a
two part cylindrical housing the parts being threadingly engageable
and housing a collet having a conical end which cooperates with a
collet closer having a conical through bore which is urged onto the
conical end by the screwing together of the housing parts to close
the collet and clamp a conductor therein. This construction again
relies on the screw action of the housing parts to effect clamping
with the requirement for two handed operation and uncertainty as to
the degree of clamping that results.
The present invention seeks to provide an improved connector the
previously mentioned disadvantages are overcome.
According to the present invention there is provided an electrical
connector comprising a tubular body having an axially extending
bore therein for receiving an incoming cable and for accommodating
electrically-conductive contact-making means located within the
tubular body and electrically coupled with contact means (e.g. pin
contact) of the connector, and axially displaceably means at least
partly received by and axially displaceable within the tubular body
and effective to cause the contact making means to make good
electrical contact with a conductor of an incoming cable in
response to a predetermined axial displacement of the displaceable
means, characterised in that in the assembled state of the
connector the displaceable means has a preclamping position
relative to the tubular body an which it acts to retain the contact
making means relative to the body to permit insertion of the
conductor, which displaceable means is accessible from outside the
tubular body to permit axial depression thereby to effect
displacement to a clamping position which establishes good
electrical contact between the contact making means and the
conductor.
The provision of a displaceable means which is accessible from
outside the tubular body and actuable by depression considerably
simplifies the operation of clamping as it does not require the
rotation of housing parts and may be effected by depression with
one hand.
The preclamping position of the displaceable means advantageously
provides for security against loss of internal connector parts
during handling, transport and/or delivery of the connector.
The displaceable means may be secured in one or each of said
preclamping and clamping positions by latching.
The latching may be effected by co-operating projection(s) and
groove(s) formed in the axially displaceable means and a
cooperating latching element to effect snap engagement with each
other in the latched position. The axially displaceable means may
be arranged to exert a radially inward force on a contact-making
element of the contact-making means to make good electrical contact
with the conductor of the cable in response to the aforesaid
predetermined axial displacement of the axially displaceable
means.
The contact-making element may comprise a compressible clamping
element adapted to fit over a bared part of the conductor within
the tubular body structure of the connector and electrically
coupled with the contact means (e.g. pin contact) of the connector.
The axially displaceable means in response to movement thereof
exerts a radially-inward compressive force on the clamping element
to cause it to clamp down on to the conductor.
The compressible clamping element may comprise a split tubular
metal part into one end of which the bared part of the conductor
extends and this clamping element may be formed integrally with the
contact means (e.g. pin contact) of the connector.
To positively ensure good electrical contact between the
compressible clamping element and the bared conductor the actual
conductor clamping region of the element may be screw-threaded or
otherwise configured to bite into the outer surface of the
conductor as clamping takes place.
The compressible clamping element may, for example, be provided
with radial slots which have a width less than the diameter of the
central diameter and which present at the periphery of a central
passage in the element for slidingly receiving the conductor, sharp
edges to bite into the outer surface of the conductor to make good
contact therewith when the clamping element is compressed. Four
such radial slots may be provided to afford a passageway of
cruciform configuration. A six slot construction of clamping
element is also especially contemplated.
The compressible clamping element may be stepped on its inner
surface in order to accommodate conductors of different
diameters.
The axially displaceable means for exerting the radial compressive
force on the clamping element may include a resilient sleeve member
which initially progressively envelops the split clamping element
compressing it radially inwards in response to axial displacement
of the displaceable means towards the rear of the connector from
the preclamping position of the displaceable means. The resilient
sleeve member may be provided by a split metal ring or by forming
the sleeve of inherent resilient material (e.g. plastics material).
The resilient sleeve may be engaged by, attached to, or formed
integrally with a tubular insulating member which is slidably
mounted in the bore of the tubular body structure at the contact
end of the connector. The contact means may be coupled to a
relatively large diameter clamping element by a split
frusto-conical section which facilitates smooth and easy transition
of the resilient sleeve member from the cone surface on to the
outer periphery of the clamping element in order to compress the
element radially inwards when the front end of the tubular
insulating member is displaced axially towards the rear end of the
connector. Displacement of the tubular insulating member may, for
example, be arrested once the resilient sleeve member is positioned
over the clamping element, as by the abutment of the rear end
portion of the member with shoulder means of a cup-shaped
insulating stop member located within the bore of the tubular
member and having a tapered opening therethrough for the passage of
the conductor of the cable.
It is also contemplated that the axially displaceable means may
include a rigid or non-resilient sleeve member which may be engaged
by, or attached to, a tubular insulating member slidably mounted in
the bore of the tubular body structure at the contact end of the
connector and which moves over resilient contact-making means in
order to exert thereon an inward pressure to cause the resilient
contact-making means to make pressure engagement with the conductor
of the cable.
In the case of a resilient sleeve member or a non-resilient sleeve
member, the sleeve member and the contact-making means co-operate
when the sleeve member is fully positioned thereon to provide
ongoing pressure engagement between the contact-making means and
the conductor of the cable without the need for a continuing
applied axial force on the sleeve member of the axially
displaceable means.
The connector construction of the present invention is especially
applicable to co-axial connectors for clamping down on to the
central conductor of a coaxial cable but it should be understood
that it could be used for making connections to the conductor or
conductors of other cables by way of single or multi-way
non-coaxial connectors.
For the purpose of gripping the incoming cable (e.g. coaxial cable)
at the end of the connector where the cable enters a suitable
strain-relief arrangement may be provided.
By way of example the present invention will now be described with
reference to the accompanying drawings in which:
FIG. 1 shows an exploded view of a coaxial cable connector
according to the present invention;
FIG. 1a shows an enlarged detail of FIG. 1;
FIG. 2 shows a longitudinal cross-sectional view of an assembled
coaxial cable connector substantially as shown in exploded form in
FIG. 1;
FIGS. 3a, 3b and 3c show different steps in the connection of an
incoming cable to the connector of FIG. 1; and,
FIG. 4 shows a longitudinal cross-sectional view of another coaxial
cable connector similar to that of FIG. 2 but having a different
cable strain relief arrangement.
Referring to FIG. 1 of the drawings, the embodiment depicted
therein in exploded form comprises a coaxial connector facilitating
a pre-conductor clamping assembled state.
The tubular body structure of the connector comprises two generally
cylindrical metal parts 22 and 23, the body part 22 having an
externally-threaded portion 24 which, as facilitated by the
integral nut head 25, can be screwed into an internally-threaded
portion (not shown) of the body part 23. The body part 22 includes
a cylindrical cavity 26 which slidingly receives a hollow
cylindrical latching member 27 of electrically insulating material.
The end of the latching member 27 which engages the base of the
cavity 26 is provided with a conical recess 28 against the surface
of which the end of the dielectric layer of an incoming coaxial
cable to the connector will abut, as will later be apparent. The
right-hand end of the latching member 27 is provided with a
radially inwardly extending lip or projection 29 and, although in
the present embodiment the latching member 27 is rendered radially
resilient by the provision of slots 30, it should be understood
that this may not be necessary, as will hereinafter become
apparent.
The latching member 27 is adapted to receive the end of a split
radially compressible metal clamping collet 31 which, in the
present embodiment is formed integrally with a contact 32 (e.g. pin
contact) of the connector connected to the collet 31 by a split
conical section 33. The internal periphery of the clamping collet
may be threaded or provided with serrations or surface
irregularities or otherwise configured in order to bite into the
outer surface of the single or stranded central conductor of the
coaxial cable during a conductor clamping operation. In the present
embodiment the metal clamping collet 31, as can best be seen from
FIG. 1a of the drawings, is split axially by means of four radial
slots 34 which define a cruciform passageway extending axially
through the collet and providing four axially extending sharp
corners or edges 34a towards the centre of the passageway where
clamping of central conductor 44 takes place. The width of the
radial slots 34 will be less than the diameter of the central
conductor but the central passage or region of the cruciform
passageway will be sufficiently large to slidingly receive the
central conductor 44 before radial compression of the collet 31
takes place to effect clamping of the conductor. During such
conductor clamping the axially extending sharp edges 34a of the
collet 31 will bite into the conductor 44 in order to ensure good
electrical contact therewith. As will readily be apparent, other
multi-slot collet constructions could alternatively be provided to
achieve a similar result. A six slot collet construction is also
especially contemplated.
A resilient split metal ring 35 is provided for cooperating with
the collet 31 to effect radial compression thereof to effect
clamping engagement with the central conductor 44 (FIG. 1a). To
achieve such compression, a tubular axially-displaceable member 36
of insulating material is provided. The ring 35 and member 36
together form axially displaceable means for effecting clamping as
will be described. The displaceable member 36 is slidably received
in a through bore 37 of the connector body part 23 and when the two
body parts 22 and 23 are secured together with the collet 31 and
the co-operating split clamping ring 35 located within the internal
cylindrical cavity of the body structure, the member 36 can readily
be displaced axially simply by exerting pressure on the right-hand
end thereof, as viewed in the drawing, so that the radially
flexible slotted end of the member 36 defined by slots 38 first
makes snap engagement with the tubular latching member 27 by the
engagement of the lip or projection 29 on the member 27 with an
external circumferential groove 39 in the slotted end of the
displaceable member 36. It will be appreciated that with the
latching member 27 slotted, as shown, the slots 38 in the member 36
could be dispensed with. As will readily be appreciated from FIG. 2
of the drawings which shows a connector very similar to the
exploded connector of FIG. 1 but in an assembled state prior to
clamping of the central cable conductor, component parts of the
connector are securely held in situ by the initial latching
arrangement provided between the members 27 and 36. Such an
arrangement importantly enables connectors to be handled and/or
transported/delivered in readiness for cable connection and
conductor clamping without the risk of connector parts becoming
detached or lost.
In order to connect the assembled connector to a coaxial cable, as
shown at 40 in FIG. 3a of the drawings, the usual outer insulation
sleeve 41 will be cut back, as shown, to expose a suitable length
of an underlying metal braided screen 42. The metal braid will then
be stripped back, as shown, over a requisite length to leave a
length of extruded dielectric insulation 43 exposed. This
dielectric will then be cut back to leave a length of bared central
conductor 44. The cable end will then be inserted through a metal
crimping ferrule, shown at 45 in FIGS. 1 and 3b, and then into the
cable receiving end of the body part 22 which is already screwed to
the body part 23 in the pre-conductor clamping assembled state of
the connector. The body part 22 has a tubular extension 46 which
may have circumferential ridges 47 so that as the cable moves into
the interior of the connector the ridged extension 46 will be urged
between the dielectric layer 43 and the metal braiding sleeve 42 of
the cable, as shown in FIG. 3b, whilst the bared end 44 of the
central conductor will move into and along the central passage of
the clamping collet 31 as indicated in FIG. 1a of the drawings,
until the forward end of the exposed dielectric material 43 abuts
against the conical surface of the recess 28 provided in the
latching member 27.
To effect clamping of the collet 21 to the central conductor 44 of
the incoming cable 40, the axially displaceable member 36 is simply
pressed from its initial pre-clamping latched position further into
the bore 37, as a result of which the split clamping ring 35 will
be forced by the displacement member 36 over the cylindrical
surface of the split collet 31 which is accordingly compressed
radially inwards so that the inner axially extending sharp edges
34a, as shown in FIG. 1a, bite into the outer surface of the single
or stranded central conductor in order to make good electrical
contact therewith. When sufficient clamping force has been exerted
on the collet 31 by movement of the clamping ring 35, the
displaceable member 36 makes a second and final snap engagement
with the latching member 27 by the engagement of a second
circumferential groove 48 in the member 36 with the inturned lip or
projection 29 on the latching member 27. In this position of the
displaceable member 36 the components of the connector are in the
conductor clamped assembled state and the resilient split clamping
ring 35 co-operates with the collet 31 to provide an ongoing
pressure engagement between the collet and the central conductor 44
without the need for a continuing axially applied force to the ring
35. In this state of the connector the cable may be pulled to carry
out a tensile test for ensuring that effective clamping of the
central conductor has been achieved.
It is contemplated that the members 27 and 36 could be composed of
a transparent insulating material which would enable a conductor
clamp connection to be viewed after unscrewing the two body parts
22 and 23.
Although in the embodiments described with reference to FIGS. 1 to
4 the sleeve member 35 comprises a resilient split ring 35 which
co-operates with the clamping element 31 to provide ongoing
pressure engagement with the central conductor 44 it will be
appreciated, as already mentioned, that the resilient sleeve member
35 could be replaced by a non-resilient sleeve member which
co-operates with resilient contact-making means over which the
sleeve member fits to provide the ongoing pressure engagement
between the contact-making means and the central conductor of the
coaxial cable.
As will be apparent, once the resilient or non-resilient sleeve
member has been moved over the contact-making means the insulating
displacement member and other parts of the connector could be
removed without unclamping of the central conductor.
In order to complete the strain relief connection between the
incoming cable 40 and the connector, the metal ferrule 45 may be
positioned over the metal braiding overlying the tubular ridged
extension 46, as can be seen in FIG. 1 of the drawings, and then
crimped down on to the braiding, as shown in FIG. 3c.
To enable the connector to be panel mounted, a radially collapsible
ring 49 may be fitted in a groove of the body part 23. The
configuration of the ring allows the contact end of the connector
to be inserted into a panel aperture after which the ring restores
to hold the connector in position.
Referring finally to FIG. 4 of the drawings this shows a coaxial
cable connector which is identical to that shown in FIG. 3 apart
from the cable strain relief arrangement.
After suitable stripping back of the outer insulation sleeve 41 and
braiding 42 of the cable 40, as shown the stepped tubular extension
46 will be forced between and effect separation of the inner
dielectric layer 43 from the braiding 42 so that the separated
outer layers of the cable extend over the extension 46. A stepped
clamping bush 50 which has radial slots 51 defining resilient arms
52 is then pressed over the extension 46 so that latches 53 at the
ends of the arms 52 make snap engagement with an internal groove 54
provided in the nut 25. In this position of the clamping bush 50,
the incoming cable is firmly clamped relative to the connector body
structure to prevent straining of the central conductor 44 which is
clamped to the clamping element/contact 32, 33.
Although the invention has been specifically described as applied
to a coaxial connector it will readily be apparant that it could be
applied to single or multi-way non-coaxial connectors.
* * * * *